An edible species known as cannonball jellyfish (Stomolophus meleagris) is abundant in coastal waters from North Carolina to Florida and in the northern Gulf of Mexico. Cannonballs surface each fall in drifts of millions. They drag down shrimpers' nets, litter beaches, sting swimmers, eat valuable oyster and clam larvae, and clog the intake valves of power plants (Moller (1980) Meeresforchung 28:90-100; Rudloe (1988) The Wilderness Coast (E. P. Dutton, N.Y.)). Cannonball jellyfish have an abundance of proteins and minerals. Analysis of the amino acid composition of mesogloea hydrolysate shows that glycinc is the most abundant amino acid, and that hydroxyproline and hydroxylysine, which are characteristic of collagen, are present. Jellyfish proteins, made almost entirely of collagen (roughly 80 to 90%), are rich in hydroxylysine and its glycosides. Kimura et al. (1983) J. Food Sci. 48:1758-1569.
Based on a study of Stomolophus nomurai, Kimura et al. reported that the major carbohydrate moiety in jellyfish collagen was the disaccharide unit glucosylgalactose. These results confirmed similar earlier findings reported by Rigby et al. (1972) Aus. J. Biol. Sci. 25:1361-3. The SDS-PAGE electrophoretic pattern revealed that the mesogloea collagen was composed of two electrophoretically distinct protein chains. Kimura et al. In contrast to jellyfish skin collagen, the mesogloea collagen was found to lack disulfide linkages based on unchanged electrophoretic mobility after treatment with the reducing agent, dithiothreitol.
In 1985, Miura et al. (1985) J. Biol. Chem. 260:15352-6, suggested that the primary mesogloea collagen of the jellyfish Stomolophus nomurai was type V, a heterotrimer of α1, α2, and α3 chains. On the other hand, Nagai et al. (1999) J. Sci. Food Agric. 79:855-858, reported that the collagen isolated from Stomolophus meleagris was type I, composed of α1α2α3-heterotrimers. The authors attributed the third chain to an exceptional type I chain present in the skin of many teleosts. Nagai et al. later reported a fourth subunit (α4) in Rhopilema asamushi jellyfish. Nagai et al. (2000) Food Chem. 70:205-208.
Collagen is generally unique to the organism, or even the type of tissue, from which it is derived. A detailed description of the structure and the biological functions of the various different types of naturally occurring collagens can be found in Lodish, ed. (1999) Molecular Cell Biology, 4th ed., (W H Freeman & Co, N.Y.). Type II collagen from chicken and cows has been used to treat rheumatoid arthritis (RA), an autoimmune disease characterized by pain, warmth, redness, swelling, and stiffness of the joints, often resulting in progressive joint destruction, deformity, and loss of function. Specifically, type II collagen has been used to induce oral tolerance in a subject suffering from RA.
Oral tolerance, first described in 1911 by Wells, refers to a state of specific immunological hyporesponsiveness to orally administered antigen. It is a long recognized method of inducing immune tolerance. The primary mechanisms by which oral tolerance is mediated include deletion, anergy, and active cellular suppression. Weiner et al. (1997) Res. Immunol. 148:528-33. The dose of the orally administered antigen determines mode, i.e., low doses favor active suppression, whereas high doses favor deletion and anergy. Friedman et al. (1994) Chem. Immunol. 58:259-90. Other parameters, such as feeding repetitions, forms of antigen, timing of administration, etc., can also influence effectiveness of oral tolerance. Oral tolerance involves the activation of suppressor T cells in the mucosa of the gut. Weiner et al. (1994) Annu. Rev. Immunol. 12:809-37.
Orally administered autoantigens suppressed autoimmunity in several animal disease models, including experimental autoimmune encephalomyelitis, Miller et al. (1993) J. NeuroimmunoL 46:73-82, uveitis, Nussenblatt et al. (1990) J. Immunol. 144(5):1689-95, myasthenia, Wang et al. (1993) J. NeuroimmunoL 44:209-14, diabetes (non-obese mouse model), Daniel et al. (1996) Proc. Natl. Acad. Sci. 93:956-60, and in adjuvant induced arthritis and collagen induced arthritis, Khare et al. (1995) J. Immunol. 155:3653-9; Matsumoto et al. (1998) Clin. Immunol, Immunopathol. 88:70-9; Yoshino et al. (1997) Arthrit. Rheumat. 38:1092-96.
Human clinical trials involving oral tolerance have been carried out for diseases such as multiple sclerosis, Weiner et al. (1994), food intolerance, Ferguson et al. (1996) Ann. N.Y. Acad. Sci. 778:202-16, and uveitis, Nussenblatt et al. (1996) Ann. N.Y. Acad. Sci. 778:325-37. Decreases in T-cell autoreactivity and other positive clinical effects have been observed, with relatively few or no negative side-effects.
Chicken and bovine type II collagen has been tested as a candidate autoantigen for inducing oral tolerance (a tolerizing antigen) in several animal models, including antigen-induced arthritis, Yoshino et al. (1995) Arthritis Rheum. 38:1092-6, adjuvant arthritis, Zhang et al. (1990) J. Immunol. 145:2489-93, pristane-induced arthritis, Thompson et al. (1993) Immunology 79:152-7, and collagen-induced arthritis, Thompson et al. (1986) Clin. Exp. Immunol. 64:581-6. Collagen-induced arthritis (CLA), for example, shares clinical, histological, immunological, and genetic features with human RA and has been used as an animal model for the study of RA for over twenty years.
Chicken and bovine type II collagen has also been found to confer a suppressing effect on RA in humans. For instance, oral administration of a solution of type II collagen prepared from chicken cartilage was successfully used to treat a group of 60 patients with severe RA by inducing oral tolerance. See Barinaga et al. (1993) Science 261:1669-70 and Trentham et al. (1993) Science 261(5129):1727-30. Researchers at the Harvard Medical School have reported that in a randomized, double-blind trial, a decrease in the number of swollen joints and tender joints occurred in subjects fed chicken type II collagen for 3 months but not in those that received a placebo; four patients in the collagen group had complete remission of the disease. The researchers concluded that oral tolerance had therapeutic efficacy for rheumatoid arthritis.
World-wide, 1% of the human population is afflicted with RA. In the United States, roughly 2% of the American population suffers from RA. For example, a 1990 study found that roughly 2.1 million American with RA, mostly persons between 20 and 45 years of age, with a higher frequency in females. Singsen (1990) Rheum. Dis. Clin. North. Am. 16:581-99. Thus, type II collagen, or collagen having similar effects, has great potential for the relief of RA in a significant number of people. Current treatment options are often unsatisfactory because of both limited efficacy and negative side-effects, such as toxicity.
Thus, due to its relative lack of side-effects, oral tolerance offers significant potential for the relief of RA. Sources of type II collagen that have been used in RA oral tolerance studies include native type II collagen from nonlathyritic chicken sternal cartilage, Trentham et al., and type II collagen from the nasal septum of cows, Sieper et al. (1996) Arthritis Rheum. 39:41-51. However, such sources are relatively expensive to obtain. Further, negative effects from delayed type hypersensitivity (DTH) have been noted, for instance, with bovine type II collagen. Of additional concern is the presence of bovine spongiform encepalopathy (BSE) in cattle and the possibility of transmission to humans fed bovine type II collagen. Accordingly, cost-effective sources of high-quality, safe, efficacious type II collagen, or collagen able to induce oral tolerance, are needed.